Circuit making and breaking device



April 17, 1928.

T. ZWEIGBERGK CIRCUIT MAKING AND BREAKING DEVICE FiledDec. 2 1925 3 Sheets-Sheet 1 April 17, 1928. 1,666,675

'r. ZWEIGBERGK CIRCUIT MAKING AND BREAKING DEVICE Filed Dec.- 20, 1923 5 Sheets-Sheet 2 April 17, 192&

T. ZWEIGBERGK CIRCUIT MAKING AND BREAKING DEVICE Filed Dec. 20, 192.3

3 Sheets-Sheet 3 Patented Apr. 17, 1928.

UNITED STATES PATENT OFFICE.

THORSTEN ZVEIGBERGK, OF LONDON, ENGLAND.

CIRCUIT MAKING AND BREAKING DEVICE.

Application filed December 20, 1923, Serial No. 681,719, and in Great Britain December 27, 1922.

This invention is concerned with circuit making and breaking devices and the general object of my invention is directed to the provision of an clectro-n'iagnctically operated circuit breaker having an independently. mechanically operated mechanism adaptable for conjoint: action with the electro-magnetic mechanism to close the circuit whereby a relatively strong force may be exerted to close the circuit breaker without necessitating the incorporation of heavy electro-magneticafly operable parts and to thereby greatly increase the breakingcharacteristics of the device under'e-lectro-magnetic control.

A further object of my. invention is the adaptation thereof in a specific form to an electric motor control system such as I disclose in my Patent No. 1,412,589 issued April 11, 1922.

Other objects ofmy invention will hereinafter be set forth in the following description which refers to the accompanying drawings illustrating an embodiment thereof adapted to an electric motor control sys stem. The essential characteristics are summarized in the claims.

In the drawings, Fig. 1 is a side elevation of a circuit breaker mechanism embodying my invention; Fig. 2 is a plan view of the device shown in Fig. 1; Fig. 3 is a crosssectional plan view taken substantially along the line of 1; Fig. 4 compr ses a diagrammatic illustration of a preferred adaptation of the circuit breaker device to an electric motor control system such as I have hereinbefore referred to.

y invention contemplates the combining of an electro-magnetically operated circuit breaker and a mechanically operated'means for positively closing the circuit breaker, the devices being combined in such manner that a conjoint action thereof is necessary to close the circuit breaker contacts but both are separately elfective'in permitting an opening of the contacts.

In carrying out the objects of my invention, the clectro-magnetic device and the mechanically operated means are preferably connected to a contact carrying member whereby either or both devices may be effective in moving the contact carrying member. A preferred form of this arrangement is shown in Fig. 1 wherein a tired contact 10 may be mounted upon a base or rigid frame 1.1. ii'iovahie contact 12 is shown as being pivot-ally mounted upon a pair of depending arms 13 which may be pivotally mounted as indicated at 14: in any suitable manner upon insulated frame members 15. An iron cladsolenoid magnet 16 is preferably mounted upon the frame portion 11 to be disposed above the arms 13 whereby a suitable link mechanism may be provided to connect the armature 17 of the electro-magnet with the arms 13. This link mechanism preferably includes a pair of togglearms 18 and 19 which are connected to an extension arm 20 of the armature 17 by intermediate l-y disposed links 21.

The toggle arms 18 and 19 also serve to connect the mechanical operating means with the arms 13 and this mechanical means in the present adaptation of my invention may comprise a cam mounted upon the shaft 26 of a main motor resistance controller drum to be hereinafter referred to. The cam 25 has formed, about the periphery thereof, a recess 26 into which a cam follower or roller 27 may ride. The roller 27 may be carried on a pair of lever members 28 which may be pivotally mounted, as indicated at 29, on downward extensions 30 of the frame members 15. The upper ends of the lever members 28 are pivotally connected at 31 to the toggle arm 19.

The contacts 10 and 12 are preferably separated by a powerful spring action which may be obtained by a spring 35 suitably mounted upon a plunger 36 supported by a bracket 37 secured to the frame of the device. One end of the plunger may be free while the other end engages an extension of a contact carrying arm 38 carried by the large arms 13. The swinging movement of the arm 38 relative to its supporting arms 13 may be suiliciently iimited whereby during the first part of the closing action of the device, the non-corroding portion 12* of the contact 12 will first contact with the non-corroding portion 10 of the rigidly mounted contact 10.

In adapting my invention to a motor control system, I provide an auxiliary switch mechanism which may be incorporated in the present mechanism in such manner as to be operated by the solenoid armature 17. As shown in Fig. 1, a plunger 40 is slidably mounted to extend through the core 41 of the solenoid whereby one end thereof may bear against the armature 17 while the other and may act upon a contact carry n (ill ber 42 and may be pivotally mounted as indicated at i?) on an extension 44L oi? the solenoid housing 16. The member 42 carries a contact block 45 having fixed contacts 46 and i? mounted thereon to cooperate with a resilient switch plate 48. T he switch plate 48 together with others to be described may be supported by an insulated bracket construction 49 carried by the extension let. A compression spring 50 may react-between the solenoid housing and a lower end 42 of the member2 to normally maintain the contact switch plate -l-8 connected with the contact 4-6 when the solenoid is being energized. This spring likewise maintains the member 12 in engagement with the rod ll). The ends of the rod 40 thus, under all conditions, are pressed between the armature 17 and the contact carrying member 11' desired, an interlocking feature to operate between the auxiliary circuit breaker mechanism and the main circuit breaker mechanism may be provided by ezrtendi the switch member 42 downwardly to engage and cooperate with an extension 13 of the arm 13. An advantage of such an arrangement will be hereinafter set forth.

A circuit breaker device such as I herein disclose, in its general principle of operation may be adapted to many uses, but the particular embodiment specific-a ly illustrated and described is adaptable for breaking the main motor line in an electric controlling system wherein the main motor current is controlled through a motor driven controller, the auxiliary motor driving this controller being regulated in its starting and stopping action by a manually operated master controller.

Such a system is diagrammatically represented in Fig. i which also includes a diagramme-tic representation of the movable elements oi my circuit breaker device in their cooperative relation to the system. It will be noted that in this diagram, the switch member, in addition to contacts 46 and 4:7 carries a ground contact and additional contacts 56. 57, 58 and 59 which cooperate with suitable resilient contacts mounted similarly to the member 48. A mast-er controller h. shown as being mounted upon the shaft 26 which carries the cam 25 of the mechanical circuit breaker operating means. The master controller is shown as being provided with seven controlling or contacting positions including the off positions as indicated by the dot and dash lines, two of which 60 and 61 are shown. The main motor controller drum M is usually rotated to a predeterminedextent by a worm wheel 6st mounted upon the shaft 26 and a worm 65 mounted upon an auxiliary motor shaft 66. The action of the auxiliary motor X is predetermined by the manually operated master controller indicated at T.

Fixed contacts C cooperate with the movable segnient contacts on the master com troller T. The positions of these contacts are indicated by dot and dash lines. Two oi the segment contacts 68 and (39 are shown in full lines. These contacts cooperate with the fixed contacts 70 and 71 respectively.

The establishing of various circuits by the master controller determines the direction of rotation or the armature ot the auxiliary motor X whereby the shaft 26 is driven forwardly or backwardly through the worm and gear and the field winding; of the auxiliary motor and the windings of the armature thereof are connected in the circuit to be under the control of the master controller. Thus when the drum of the main controller is in the oil position as shown in Fig. 2, the tired contacts 60 and 61 (one of which is grounded) are bridged by moving contact segment 81 on the main motor controller drum for a purpose to be hereinafter described.

il hen the operator shifts the master controller T to its first position, segment con tacts 68 and 69 are brought into engagement with contact 71 and current from an auxiliary source passes through these contacts to the solenoid line 90. Solenoid coil S is thus energized due to the mnding of the solenoid line 91 through co itacts 60, (31 and 81 respectively and which normally connect the line 91 to ground 92. The armature 17 is consequently attracted by the solenoid coil. The solenoid extension 20 moves the swinging link 21 in a downward direction thus bringing the toggle arms 18 and 19 to a position not quite in alignment. The arms 13 are thus swung to the left. bringing the main motor line contact 12 or" the circuit breaker into juxtaposithm with the fixed contact 10 of the circuit breaker. This action of the solenoid turough the link connections therefore ()VETUOH' part oi the force oi the spring 35. The enoid armature, by reason of its act m upon the plunger 40 reacts upon the switch member 12 thus bringing the'conlacts 58. l? and as into circuit closing relation and the line and 95, connected, therewith. establishes energization of the auxiliary motor. the current being grounded tl'irough, contacts and 55 to ground 97. The auxiliary motor thus rotates the cam shatt to b:' the contact segments on the main moto controller drum to first position thus ei'stablishing a current supply to the main motors. At this point, the relationship of the contacts between the master controller T and the main motor controller M is such that the winding of a relay switch solenoid indicated at R is deen r 'ized, the relay drops and short circuits the auxiliary motor armature lines 94 and 95 thus stopping the auxiliary motor.

KOO

It will be seen that by reason of this first movement of the controller drum shaft 26, the cam 25 is rotated sufiiciently to advance the roller 27 out of the recess of the cam and this action causes a rocking movement of circuit breaker arms 28 and the arms 28 react upon the arms 13 through the toggle members 18 and 19 to positively and forcefully position the movable main motor line contact 12 upon the contact 10. The contacts 10 and 12 thus close a circuit between the source of the main current and the main motors, which current passes through appropriate resistances controlled by cams (not shown) on the shaft 26 and the-main motors are consequently started with the proper supply of current.

It should be noted that when the main controller drum advanced. to its first controlling position, the solenoid circuit 91 is opened by reason of the contact segn'ient 81 being shifted out of engagement with contact and 61 and to maintain a continued energization of the magnet, I provide a con- 'nection on. the switch member 42 for mainto corresondin successive aositions each position corresponding to further resistance being cut out of the main motor circuit by switches, (not shown) actuated by cams carried on the drum shaft 26. The relay circuit will be energized anddeenergized in the manner described for each step.

\Vhen it is desired to deenergizc the main motors, the master controller T" may be shifted to its off-position, thus cutting elf the supply of current to the solenoid coil. \Vhen the solenoid coil. is thus deenergized, the armature will. drop until arrested in its movement by the bumper spring 9 and the toggle links will thereupon collapse under the in fluence of spring 35, thus permitting the contacts to be sprung apart and the main motor current is thereby interrupted. This action takes place regardless of the relation of the cam follower 27 to the notch 28 of the cam 25.

Simultaneously with the release of the armature 17, the switch member 42 is shifted inwardly toward the solenoid by reason of the action of the spring 50 and a current is thereby established in the field windings of the auxiliary motor through the line 98 by reason of the contacts 58, 4:7 and 57 through lines 94, 95 to 48,46 and ground 96 establishing a grounded connection of this line which. is always connected to a source of current. The auxiliary armature is thus driven in an opposite direction and the drum shaft 26 rotated in a reverse direction to bring the cam recess 28 into proper starting relation to the cam follower 27. This reverse rotation of the drum shaft 26 is continued until the drum is returned to initial off-position whence the auxiliary field circuit is interrupted by disengagement of contacts, (not shown) which are relatively movable consequent to this rotation of the drum shaft.

It should here be noted that the operator cannot energize the solenoid magnet by any subsequent shifting of the master controller to a running position until the auxiliary motor has completed its reverse rotation to bring the main motor controller drum bacl:

to its olf-position whereby the solenoid circuit is completed by contacts 60, 61 and 81.

The purpose of an interlocking mechanism between the two switch devices of the circuit breaker will now be set forth. It sometimes occurs that when a circuit breaker operating in a system such as I herein disclose is subjected to an unusually heavy passage of current through the contacts,thus causing burning or arcing thereof and un der exceptional circumstances a heavy rush of current, may cause the welding together of the contacts thus rendering ineffective the responsive characteristics of the circuit breaker.

To meet such a contingency two of the circuit breakers may be arranged side by side for joint cooperation in series and the cams for operating these two mechanisms may be carried, for instance, by the drum shaft 26 and may be so associated that one breaker closes slightly before the other. The damaging efi'ect of an unusual rush of current would then be present at the contacts of only one of the circuit breakers thus leaving the other in operative condition to interrupt the circuit at the desired time. It is desirable, however, that when two breakers are thus used that either one be prevented from reclosing if the other were to have the contacts fused together. The foregoing conditions may be met, however, by the provision of only one auxiliary switch mechanism, and the contact carrying member thereof may be provided with an extension in the nature of a depending arm 42 to engage and interlock on a projection. 13" formed on the extension 13 of the contact carrying arm 13. The extension 42 consequently cannot pass this projection 13" in the event the contacts are fused together and the switch member 42 thus prevented in its movement. Shifting of the contacts carried thereby, whereby the auxiliary motor is caused to rotate in a reverse direction to bring the main motor con troller drum to the off-position prevented and until this is effected the breaker which is arranged to close slightly before the other breaker is closed cannot be closed again due to the Lin-alignment of the recess of its cam with its cam follower.

From the foregoing description oi"- my invention it will be readily apparent that the solenoid and parts actuated thereby may be comparatively lic'ht in construction due to the fact that I obtain a positive relatively powerful closing of the contacts of the circuit breaker by mechanical means. I there fore obtain a very rapid breaking action or parting action of the contacts by the use of a spring member which. may be much lighter than would otherwise be necessary.

It will also be apparent that if desired the circuit breaker contacts could be opened. and closed by the mechanical action of the cam and connecting levers acting on the movable contact arms when the armature of the solenoid is in its attracted position. It would also be possible to close the circuit breaker contacts as well as to open them by energizing the solenoid. magnet to set the contacts against the full force of the spring when the mechanically operated parts of the device are in such condition that the roller or follower is out of the cam recess. Such a closing action, however, would necessitate the use of a more powerful magnet and a heavier construction of all the associated parts, thus depreciating the rapid breaking characteristics that l otherwise obtain when the final closinc' is effected mechanically.

It is to be Iurther understood that the specific form of construction herein set forth, is shown as being;- particularly adapted to electric motor control systems merely for the purpose of illustrating the adaptabih ity oi": my invention to practical uses and that the scope of the invention is not to be understood as being confined to the details herein. described.

I claim:

1. In a circuit making and breaking device, the combination of a pair of contacts, means for el'l ectinp a relative movement be tween the contacts and electromagnetically actuated mechanism acting; on said means to move one of the contacts anc. a mecl'ianically operated means acting through the electromagnetically actuated means to snpg'ilement the movement of the contact and completely close the contacts whereby the electromz-ignetically actuated means moves the contact during one time interval and the mechanical means completes the movement in another time interval.

2. A circuit breaker of the character described, having in combination a pair of relatively movable contacts, electromagnetic means for effecting; said relative movement, said eleetrcmagnetic'means including sole-- device between the auxilh noid, a casingtherefor and a plunger eXtending therethrouglna mechanically operated means for ellecting said movement, a mechanism operatively connecting both the said means whereby either may be effected in causing said relative movement of the contacts, an auxiliary reversing switch mechanism pivotally mounted on the casing, and resiliently urged into contact with the plunger and adapted to be actuated by the electromae' etic means, and an interlocking switch mechanism and the contact moving mechanism.

3. A circuit breaker of the character described, having in combination a pair of relatively movable contacts, electro-magnetic means for effecting said relative movement and mechanically operated means for effecting saidmovement a mechanism operatively connecting both of said means whereby either may be eltectivein causing said rela tive movement of the contacts an auxiliary switch mechanism actuated by the electro magnetically operated means, and an interlocking device between the auxiliary switch mechanism and the contact moving mechanism.

l. In a circuit breaker the combination of a. pair of separable contacts, a mechanical means :lor closing the contacts, electro-magnetically operated means for eli ecting a relative movement oi the contacts, an electromagnet therefore, a second pair of relatively movable contacts, means actuated by the electromagnetically operated means for causing movement of said last named contacts, and means for preventing relative movement of the last named contacts when the first named contact-s fail to separate upon the deenergization of the electromagnet.

5. lln a circuit breaker the combination of a pair of separable contacts, a mechanical means for closing the supports, electro mag netically operated means for effecting a relatire movement of the contacts, a second pair of relatively movable contacts, a shittabic support therefor, means actuated by the electro-magnetically operated means for causing movement of the support and means iEor interlocking the support and the mechanically operated means in the event the contacts are fused together.

6. In a circuit breaker the combination of a pair of: separable contacts, electro-magnetically operated means for effectinga rel a tive movement of the contacts, an electriv magnet therctor, a second pair 0? rel ativcly movable contacts and means for prevei'iting movement of the contacts when said firs named contacts fail to separate upon the deenergization of the electromagnet.

7 In a circuit breaker, the combination of a pair of relatively movable contacts, an electro-magnetically operated means cl? 1 Stil -C". KHOVQD. who;

therefor, a mechanically operative means also effective to cause said movement, said mechanical means being ineffective to close the contacts precedent to actuation of the electro-magnetically operated means, an auxiliary switch mechanism adapted to be actuated by the electro-magnetically operated means prior to the closing of the relatively movable contacts by the mechanical means and an interlocking cfivice adapted to prevent movement of the switch mechanism in the eventsaid contacts fail to separate consequent to the deenergization ot the magnet.

8. In a circuit making and breaking device, the combination of relatively movable contacts, movable means supporting one of the contacts, electro-magnetic means for actuating said movable means, a toggle arranged whereby the electro-magnetically operated members may etfect a preliminary closing movement of said contact supporting means and mechanically operated means acting on the toggle to effect a final positive closing movement of the contacts.

9. In a circuit making and breaking device, the combination of relatively movable contacts, movable means supporting one of the contacts, electro-lnagnetically O)Cl'lli.(ill means for actuating the movable supporting means including a toggle arranged whereby the electro-magnetically operated means may etfect a preliminary closing moven'ient of said contact supporting men'ibers and mechanically operated means acting on the toggle to etlect a final positive closing movement of the contacts, the association of the two devices being such that the electro magnetically operated means may be actuated to permit releasing of the toggle independently of any movement of the mechanically operated means.

10. In a circuit breaker device the combination ot a pair of relatively movable contacts, electroanagnetically operated means for effecting a closing movement of the contacts, a resilient means opposing said movement and'adapted to normally maintain the contacts separated, the electro-magnetically operated means being effective to overcome only a part of the opposition of said resilient means and a mechanically operated means for completing the closing movement of the contacts by a positive application of force in opposition to said resilient means.

11. In a circuit breaker device the combination of a pair of relatively movable contacts, electro-magnetically operated means for eifecting a partial closing movement of the contacts, a resilient means opposing said movement and adapted to normally main tain the contacts separated, and a mechanically operated means for completing the closing movement of the contacts by a positive application of force in opposition to said resilient means.

12. In a circuit breaker device the combination of a pair of relatively movable contacts, electro-magnetically operated means for etfccting a closing movement of the con tacts, resilient means opposing said movement and adapted to normally maintain the contacts separated, a mechanically operated means for con'ipleting the closing movement of the contacts by a positive application of force in opposition to said resilient means, an auxiliary switch mechanism operated by the electro-magnetically operated means and a locking mechanism for preventing actuation of the switch mechanism when said resilient means fails to separate the contacts.

13. In a circuit making and breaking device, the combination with a pair of relatively movable contacts of electro-magnetically operated means for effecting a partial closing movement of the contacts, an eleetromagnet therefor, a mechanicallyoperated means for completing said closing movement, and auxiliary switch mechanism operated by one of said means, said auxiliary switch mechanism including an interlocking device whereby its operation is prevented upon failure of the contacts to separate when the electro-magnet is deenergized.

14. In a circuit making and breaking device, the combination with a pair of relatively movable contacts of an clectro-magnetically operated means for effecting a partial closing movement of the contacts, a mechanically operated means for completing said closing movement, an auxiliary switch mechanism operated by one of said means, said auxiliary switch mechanism including an interlocking device adapted to engage the mechanically operated means to prevent op eration of the switch mechanism upon failure of the contacts to separate.

15. In a circuit making and breaking device, the combination with a pair of relatively movable contacts of an electro-magnetically operated means for effecting a partial closing movement of the contacts, one of the contacts being mounted on a movable member, a mechanically operated means for completing said closing movement, an auxiliary switch mechanism operated by the electro-magnetically operated means, said auxiliary switch .mechanism including a locking device engaging the contact carrying member whereby its operation is prevented upon t'ailure of the contacts to separate when the electro-magnetically operated means is rendered inactive.

In testimony whereof, I hereunto afiix my signature.

THORSTEN ZWEIGBERGK. 

